Unfortunately, as my last visit to The Home Depot confirmed, the prices for LED replacements for incandescent bulbs for general home lighting are still too high. The sales pitch is still that the money saved in "x" years on your electric bill and not having to buy replacement bulbs makes the LED lamps worthwhile. People are still too cautious in spending today's dollar on some potential future saving. There's always the chance that LED technology will be surpassed by research on triboluminescentsquirrelfur.

Indoor light pollution can be detrimental to your mental health. A recent study by neuroscientists at the Ohio State UniversityWexner Medical Center demonstrated that chronic exposure to dim light at night leads to depression in hamsters.[1] Hamsters, when exposed to light at night over a four week period, displayed symptoms of depression. These symptoms, which also appeared as changes in the hamster brain, disappeared after a two weeks of a normal day-night cycle. If we can generalize this to humans, it might explain the growing rate of depression during our last five centuries.[1]

Bogard writes about light pollution of the night sky, but from a personal perspective. Having experienced a truly dark sky in childhood at his family cabin on a Minnesotalake, he bemoans the fact that 80% of today's children in the United States will never see the Milky Way.[2] He then recounts other reasons why we should strive for a darker night.

According to Bogard, sky illumination at night has been increasing at about six percent per year in the United States and Western Europe.[2] Mitigation of light pollution would also lead to an energy-savings. Street lights would be more efficient if they illuminated more of the street, and less of the sky. I'm often upset at the wasted energy of shopping centerparking lots illuminated through the night when none of the shops are open, possibly because someone forget to throw a switch, or a timer is broken.

LED street lighting and diminished public lighting after midnight are among the mitigation strategies mentioned in Bogard's article. Bogard is not a scientist, so his article waxes philosophical about the solitude, quiet and stillness that accompany darkness. He mentions Van Gogh's "The Starry Night."[2] In the truly dark skies of our ancestors, the Milky Way was prominent enough to cast a shadow.